import java.util.Scanner;

public class JudgingPrimeNumbers {
    public static void main(String[] args) {
        //1不是素数

        Scanner scanner = new Scanner(System.in);
        int a = scanner.nextInt();
        boolean b = true;
                for(int i=2;i<a;i++) {
                    if(a%i==0) {
                        System.out.println("不是素数");
                        b = false;
                        break;
                    }
                }
                if(b) {
                    System.out.println(a + "是素数");
                }

    }
}
